This one may not be gluten free the way I made it, however if you substitute the flour based bread with a gluten free style, you'll be there. I was trying to figure out how to make something quick, but I wanted it to be filling as well, and I didn't have much on hand. I did have:
2 slices bread (gf option) toasted
about 3 slices, 1/4 inch thick or so, of tofu
2 teaspoons soy sauce
2 teaspoons rice wine vinegar
1 teaspoon oil (peanut worked here)
1 tablespoon "nayonnaise"
1/4 of a green pepper, sliced
1/8 of a medium onion, sliced
1 teaspoon mustard
celery salt, pepper, and paprika to taste
Soak the tofu slices in the soy sauce and vinegar for a few minutes. Heat up the oil in a saute pan and add the green pepper and onion, seasoning to taste. After a minute or two, flip the veg and add the tofu, lightly browning both sides. Once that is complete, stack your sandwich and garnish with vegan mayo and mustard. Maybe even tobasco if you care to be so bold.